Really clever main mechanic, though the way you can pass through lines of your color but collide with walls of your color quickly becomes rather confusing.
Like when you have "oh I'm red so I should be able to stand on this red line" thoughts, or the fact that everyone can walk through white lines that look like doors you have to unlock. I'd consider using blocks fully of one color to make things like the wall at the end of level 6 a bit clearer. I would've also appreciated some music, even if it was not made during the jam.
That being said, There's some really clever puzzles and platforming challenges you can do with this, and the levels you designed really showcase this. There's also some really cool moments like the tunnel in level 5.